Multi-position vacuum motor



March 17, 1964 M L. CRIPE MULTI-POSITION VACUUM MOTOR Filed Oct. 2, 1961INVENTOR. M L (X/P5 United States Patent Delaware Filed Get. 2, 1961,Ser. No. 142,194 3 Claims. (61. 91-357) The present invention relates toa multi-position vacuum motor and control system therefor; and moreparticularly to an inexpensive multi-position vacuum motor having acurtain diaphragm which rolls over a vacuum port to establish oneposition of the motor.

An object of the present invention is the provision of a new andimproved multi-position vacuum motor which is simple in design, ruggedin construction and inexpensive to manufacture.

A further object of the present invention is the provision of a new andimproved multi-position vacuum motor of the above described type whereina curtain diaphragm having substantially no frictional hysteresis isused to roll over a vacuum port to both actuate the unit and provide avalving function which establishes an intermediate position of themotor.

The invention resides in certain constructions and combinations andarrangements of parts; and ftuther objects and advantages of theinvention will become apparent to those skilled in the art to which itrelates from the following description of the preferred embodimentdescribed with reference to the accompanying drawing forming a part ofthis specification, and in which:

FIGURE 1 is a somewhat schematic view of a vacuum motor control systemfor actuating the heater control of an automotive vehicle, and in whichthe vacuum motor is shown in cross section; and

FIGURE 2 is a fragmentary cross sectional view taken approximately onthe line 2-2 of FIGURE 1.

The vacuum motor control system shown in FIGURE 1 is depicted as beingused to actuate a valving structure It in the plenum chamber 12 of anautomotive heating system. The plenum chamber 12 is an elongatedstructure having a cross section that is generally a sector of a circle.A heat outlet port 14 is located across the bottom curved section of theplenum chamber; and heated air is fed into the plenum chamber through acircular inlet 16 in one endwall of the plenum chamber 12. Valvestructure has a circular end portion 18 adapted to slide over and closeoff the outlet port 14, and an end actuating arm portion Zil whichoverlies the inlet 16 in the endwall of the plenum chamber and isfastened to an actuating shaft 22. The valving structure 10 is shown inits Olf" position wherein heat is prevented from entering the plenumchamber 12.

The heater control shown is also provided with a defrosting connection24 in its endwall adjacent the heat inlet 16. The defrosting connection24 is located to the side of the normal position of the valvingstructure 10 shown in the drawing and is adapted to be closed oh by theend arm 20 as the valving structure is moved from the Off position shownto a Car Heat position wherein the circular portion 18 is open withrespect to the outlet port 14. The position just described wherein thecar heat port is open, and the defroster port is closed forms the FirstActuated position of the valving structure it). Valving structure 10 isadapted to be moved into still a Second Actuated position spacedclockwise from the First Actuated position above described, and whereinboth the defrosting connection 24 and the heat outlet port 14 areopened. The shaft 22 is rotated by means of an arm 26, and the Normal,First Actuated, and Second Actuated position of the arm 26 are in-3,125,001 Patented Mar. 17, 1964 'ice dicated in the drawings by Off,Car Heat and DEF, respectively.

The arm 26 is adapted to be moved into each of its three positions bymeans of a vacuum motor A which in turn is controlled by means remotelylocated valve structure B. The vacuum motor A generally comprises acup-shaped housing 30 having a generally axially extending internalchamber 32 which communicates with the open end of the cup-shapedhousing 30. The closed or bottom endwall 34 is provided with an axiallyextending opening 36 therethrough through which a shaft 38 is sealinglyguided for reciprocatory motion. The inner end of the shaft 38 issuitably fastened to a cup-shaped movable wall 4% whose sidewalls 42project into the internal chamber 32 and have a generally predeterminedclearance with respect to the sidewalls 44 of the chamber 32. Theinternal chamber 32 is closed off by means of a diaphragm 46, the centerportion of which overlies the movable wall 40 and the outer portion ofwhich is sealingly snapped over the radial flange 48 of the housingmember 3h adjacent. its open end. The diaphragm 46 is provided with anannular curtain portion 50 having a generally U-shaped cross section,the sides of which lay up against the sidewalls 42 and 44 respectively.Inward movement of the movable wall 40 therefore causes one leg of thecurtain portion of the diaphragm 50 to roll out of engagement with thesidewalls 42 and into engagement with the sidewalls 44 of the internalchamber 32. The shaft 38 is provided with an annular abutment washer 52suitably aiiixed to its outer end; and the abutment washer 52 isnormally biased into engagement with the end surface of the housing 30by means of a piston return spring 54- interpositioned between themovable wall 40 and the inner endwall 34 of the housing member.Reciprocatory motion of the shaft 38 is transmitted to the arm 26 of theheater control structure by means of a drag link 55, the ends of whichare suitably pivoted to shaft 38 and arm 26 respectively.

The power actuated elements 40 and 46 of the vacuum motor A are causedto move into a First Actuated position corresponding to the Car Heatposition of the lever 26 indicated in the drawing, and to a SecondActuated position corresponding to the Defrost position of the lever 26indicated in the drawing, by admitting vacuum into the internal chamber32 of the vacuum motor A. According to principles of the presentinvention, the First Actuated position of the vacuum motor A isestablished by communicating vacuum to the internal chamber 32 through avacuum connection 60 that is so located in the sidewalls 44 of thehousing 30 as to be covered up by the rolling action of the diaphragm 50at the position corresponding to the Car Heat position of the actuatingarm 26. Inasmuch as a valving action and not a positive stoppingarrangement is used to establish the First Actuated position of thevacuum motor A, it will be seen that inertia forces, frictionalhysteresis forces, etc., could cause the First Actuated position whichis assumed by the motor to vary appreciably. The overall design of thevacuum motor A shown in FIGURE 1 of the drawings is such that: thecurtain diaphragm produces substantially no frictional hysteresis, themovable elements have very little inertia by reason of their lightweight and short stroke; and the motor utilizes a piston return spring54 having an appreciable spring rate which requires increasing pressureforces to be used to move the movable wall to throughout its stroke. Thesliding fit or seal between the shaft 38 and its receiving bore 36allows a slight seepage of air into the internal chamber 32, so that ifany overshooting of the First Actuated position occurs, the movable wall40 will move outwardly to the position where the diaphragm 50 justcloses off the vacuum inlet port 60. It will further be 3% seen that theclosing off of the vacuum inlet 60 by the diaphragm 46 occurs through arolling action or the diaphragm so that no ripping or tearing of thesurface of the diaphragm occurs due to a rubbing or sliding action overthe opening of the vacuum inlet 60, as occurs in a sliding type of seal.

The Second Actuated position of the servomotor is established bysuitable abutment means, as for example the end of the sidewalls 42moving in engagement with the bottom end wall 34 of the housing, whichlimits the travel of the shaft 38 at the time that the arm 26 is in theexact Defrost position shown in the drawing. The movable elements 40 and46 are caused to move from the First Actuated position to the SecondActuated posi tion by admitting vacuum into the internal chamber 32through a second vacuum inlet connection 62 which is not valved oil inany manner by the motor, so as to positively maintain abutment cf theend of the sidewalls 42 with the endiwalls 3 4 of the vacuum motor A. Itwill therefore be seen that the movable elements of the vacuum motor Aare caused to assume First and Second actuated posi tions which areaccurately located, and adjusted to, without the use of valvingstructure provided expressly for that purpose.

Control of the vacuum motor A is had by a remotely located valvestructure B which selectively communicates vacuum to the vacuum inletports 60 and 62 of the motor A. The remotely located valve structure Bmay be of any suitable type, and as shown in the drawing is formed by arotary valve arrangement having a cup shaped body 64 into which a rotaryslide 66 is sealingly fitted. The rotary slide 66 is provided with ashaft 68 which extends through the bottom of the cup-shaped body 64, andwhich is held in place by means of :a spring 70 interpositioned betweenthe bottom of the cup and a snap ring 72 on the projecting end of theshaft 68. The bottom surface of the slide 66, and the internal surfaceof the cup-shaped body 64 form a valve porting arrangement whichselectively communicates vacuum to a first outlet connection 74communicating with the vacuum connection 60 of the motor A, and a secondoutlet connection 76 connnunicating with the second vacuum inlet 62 ofthe motor A. The vacuum connection 78, and the vacuum outlets 74 and 76are formed as part of the valve body 64 and have portings therein whichcommunicate with the internal surface of the body 64 at generallyequi-spaced intervals. The inner surface of the slide 66 is providedwith an arcuate groove 80 of sufiicient length as to be capable ofextending over all of the ports of the connections 78, 74 and 76. In thenormal Off position of the valve, the groove 80 is positioned so that itonly overlies the vacuum inlet port 78. The slide can then be rotated toa Car Heat position wherein the groove '80 overlies the ports of thevacuum inlet and actuating ports 78 and 74 and has a Defrosting positionwherein the groove 80 overlies the ports of all of the connections 7 8,74 and 76. When the slide 66 is moved into the Car Heat position, vacuumfrom the connection 78 is only communicated to the outlet 74 of thevalve body so that vacuum only enters the internal chamber 32 of thevacuum motor A through the vacuum inlet connection 60. This draws themovable elements 40 and 46 inwardly to its First Actuated positionwherein the diaphragm 50 just closes off the inlet connection 60, andproceeds no further as previously explained by reason of the very lowfriction and inertia, and the slight seepage of air between the shaft 38and receiving bore 36. When the slide 66 is moved into its Defrostposition, vacuum is also communicated to the inlet port 62 to draw themovable wall 40 down into engagement with the bottom endwall 34 of thehousing 32, and thereafter hold it in abutment therewith.

The internal surface of the cup shaped body 64 may also be provided withan atmospheric port 82, and a groove 84, in the inner surface of theslide 66 to communicate atmospheric pressure to the port 76 when the lslide 66 is in the Off position shown in the drawing. With thisarrangement, a quick passage of air proceeds to the internal chamber 32of the vacuum motor A when the slide 66 is moved to the Off position topermit the piston return spring 54 to snap the movable wall 40 and shaft38 back to its normal position, wherein the annular abutment washer 52engages the end wall of the servomotor, and the arm 26 is positioned inits Off position.

It will be apparent that the objects heretofore enumerated as well asothers have been accomplished; and that there has been provided anoverall design of a multi-position vacuum motor which is extremelysimple and inexpensive to manufacture and which will accurately positionitself into an intermediate position by the rolling action of its powerdiaphragm over a vacuum inlet pout.

While the invention has been described in considerable detail, I do notwish to be limited to the particular construction shown and described;and it is my intention to cover hereby all novel adaptations,modifications and arrangements thereof which come within the practice ofthose skilled in the art to which the invention relates.

I claim:

1. In a vacuum motor control system: a housing having an internalchamber, a movable wall in said internal chamber, the sides of saidmovable wall having a predetermined clearance with respect to thesidewalls of said chamber, a curtain diaphragm overlying said movablewall with a rolling U-shaped portion extending into said predeterminedclearance to roll between the sidewalls of said chamber and the surfaceof said movable wall during movement of said movable wall, said curtaindiaphragm having its outer edge sealingly fixed to the sidewalls of saidhousing, a driven shaft operatively connected to said movable wall,means biasing said movable wall to a normal position adjacent the openend of said internal chamber, a first vacuum connection in the sidewallsof said internal chamber spaced inwardly of the normal position of saiddiaphragm and rolled over and sealed off by said diaphragm during inwardmovement of said movable wall from said normal position to provide afirst actuated position of said driven shaft, which scaling ismaintained throughout any further inward movement of said movable wall,abutment means limiting inward movement of said movable wall to a secondactuated position wherein said movable wall is spaced inwardly from saidfirst actuated position, a second vacuum connection to said internalchamber and not closed off by said diaphragm to cause said movable wallto engage said abutment and provide a second actuated position of saidshaft, and a valve means for selectively applying vacuum to respectivefirst and second vacuum connections.

2. In a vacuum motor control system: a cup-shaped housing having agenerally closed bottom end wall and an internal chamber openingoutwardly of the open end of said cup-shaped housing, a movable wall insaid internal chamber, the sides of said movable wall having apredetermined clearance with respect to the sidewalls of said chamber, acurtain diaphragm overlying said movable wall with a rolling U-shapedportion extending into said predetermined clearance to roll between thesidewalls of said chamber and the surface of said movable wall duringmovement of said movable Wall and its outer edge sealingly fixed to thesidewalls of said housing, a driven shaft extending through said endwall of said housing and abutted by said movable wall, means biasingsaid movable wall to a normal position adjacent the open end of saidinternal chamber, a first vacuum connection in the sidewalls of saidinternal chamber spaced inwardly cf the normal position of saiddiaphragm and rolled over and sealed off by said diaphragm during inwardmovement of said movable wall from said normal position to provide afirst actuated position of said driven shaft, which sealing of saidfirst vacuum connection is maintained throughout any further inwardmovement of said movable wall, abutment means limiting inward movementof said movable wall to a second actuated position wherein said movablewall is spaced inwardly from said first actuated position, a secondvacuum connection to said internal chamber and not closed ofi by saiddiaphragm to cause said movable wall to engage said abutment and providea second actuated position of said shaft, and valve means forselectively applying vacuum to respective first and second vacuumconnections.

3. In a vacuum motor control system: a housing having an internalchamber; a movable wall in said internal chamber; a driven shaftoperatively connected to said movable wall; a first vacuum connection tosaid internal chamber; a second va'cluum connection to said internalchamber spaced from said first vacuum connection; a valve means forselectively applying vacuum to respective first and second vacuumconnections; and a diaphragm means operatively connected to said movablewall and References Cited in the file of this patent UNITED STATESPATENTS 1,809,491 Rowell June 9, 1931 1,952,806 Hyland Mar. 27, 19342,465,714 Elliott Mar. 29, 1949 2,895,455 Clowe-s July 21, 19592,986,125 Young et a1 May 30, 1961

1. IN A VACUUM MOTOR CONTROL SYSTEM: A HOUSING HAVING AN INTERNALCHAMBER, A MOVABLE WALL IN SAID INTERNAL CHAMBER, THE SIDES OF SAIDMOVABLE WALL HAVING A PREDETERMINED CLEARANCE WITH RESPECT TO THESIDEWALLS OF SAID CHAMBER, A CURTAIN DIAPHRAGM OVERLYING SAID MOVABLEWALL WITH A ROLLING U-SHAPED PORTION EXTENDING INTO SAID PREDETERMINEDCLEARANCE TO ROLL BETWEEN THE SIDEWALLS OF SAID CHAMBER AND THE SURFACEOF SAID MOVABLE WALL DURING MOVEMENT OF SAID MOVABLE WALL, SAID CURTAINDIAPHRAGM HAVING ITS OUTER EDGE SEALINGLY FIXED TO THE SIDEWALLS OF SAIDHOUSING, A DRIVEN SHAFT OPERATIVELY CONNECTED TO SAID MOVABLE WALL,MEANS BIASING SAID MOVABLE WALL TO A NORMAL POSITION ADJACENT THE OPENEND OF SAID INTERNAL CHAMBER, A FIRST VACUUM CONNECTION IN THE SIDEWALLSOF SAID INTERNAL CHAMBER SPACED INWARDLY OF THE NORMAL POSITION OF SAIDDIAPHRAGM AND ROLLED OVER AND SEALED OFF BY SAID DIAPHRAGM DURING INWARDMOVEMENT OF SAID MOVABLE WALL FROM SAID NORMAL POSITION TO PROVIDE AFIRST ACTUATED POSITION OF SAID DRIVEN SHAFT, WHICH SEALING ISMAINTAINED THROUGHOUT ANY FURTHER INWARD MOVEMENT OF SAID MOVABLE WALL,ABUTMENT MEANS LIMITING INWARD MOVEMENT OF SAID MOVABLE WALL TO A SECONDACTUATED POSITION WHEREIN SAID MOVABLE WALL IS SPACED INWARDLY FROM SAIDFIRST ACTUATED POSITION, A SECOND VACUUM CONNECTION TO SAID INTERNALCHAMBER AND NOT CLOSED OFF BY SAID DIAPHRAGM TO CAUSE SAID MOVABLE WALLTO ENGAGE SAID ABUTMENT AND PROVIDE A SECOND ACTUATED POSITION OF SAIDSHAFT, AND A VALVE MEANS FOR SELECTIVELY APPLYING VACUUM TO RESPECTIVEFIRST AND SECOND VACUUM CONNECTIONS.